Q clearance is the DOE equivalent of a Top Secret clearance. While TS is technically the highest clearance, there are many controls for compartmentalized intelligence which require SCI (sensitive compartmentalized information) and code word - Talent Keyhole, Human Control Systems, Gamma, Umbra, etc. There are also rumored clearance levels above TS.
Q clearance is the DOE equivalent of a Top Secret clearance. While TS is technically the highest clearance, there are many controls for compartmentalized intelligence which require SCI (sensitive compartmentalized information) and code word - Talent Keyhole, Human Control Systems, Gamma, Umbra, etc. There are also rumored clearance levels above TS.